It's a Tuesday night in the middle of August, and the restaurant at the Chateau Marmont is packed with a daunting collection of people who look beautiful or important or famous—or, as it may be, merely aspirational. A fetching hostess brings me to the table where the author Helen Fielding awaits, sipping at a white-wine spritzer, her short nails painted a chic shade of taupey gray. She is wearing a simple, off-white silk dress, a few tasteful pieces of gold jewelry (including a pair of Elsa Peretti earrings I've always coveted), and an oversize watch. Within minutes—make that seconds—of my sitting down, the two of us are chatting away like old friends and each ordering the hearty chicken dish instead of one of the more delicate entrées on the menu.

I'm not sure what I was expecting, but it probably was someone more like her famously discombobulated fictional heroine, Bridget Jones, and less like the poised and elegantly dressed woman with striking blue-green eyes and a dimpled smile who sits across from me. Fielding, of course, sprang into the spotlight in 1996 with the publication of Bridget Jones's Diary, which, fresh from its successful run in England, became a megahit on these shores. The novel, based on an anonymous column Fielding wrote for The Independent, introduced an American audience to the hilarious and occasionally poignant world of Bridget Jones, a thirtysomething "singleton" who strives heroically to contain her caloric intake, kick her addictions to cigarettes and booze, and find a suitable mate in between suffering through the dinner parties of "Smug Marrieds" and falling for "emotional fuckwits." A sequel, Bridget Jones: The Edge of Reason, followed here in 1999, further familiarizing readers with Bridget's antic energy and on-again, off-again romance with Mark Darcy. The cultural impact of the books was vouchsafed with the release in 2001 of the critically praised film adaptation of the first novel, starring Renée Zellweger, Colin Firth, and Hugh Grant, with a script cowritten by Fielding.

Now, 14 years and much life experience later, Fielding is back with a third installment, called Bridget Jones: Mad About the Boy. Set to be published worldwide on October 15, the new novel is generating palpable excitement at her publisher, Alfred A. Knopf, which has announced a first printing of a whopping 250,000 copies. The company's chief, Sonny Mehta, has been a die-hard fan since he lost the bidding war for the right to publish Fielding's first Bridget sortie: "It made me laugh very much," he observes. "I just thought that the book was one of the freshest things I'd read. Chick lit hadn't been invented yet. I was absolutely charmed by the voice, although I wasn't sure how universal it was." Mehta is convinced that a "fanatical following who've aged along with Bridget" will grab up the new novel. "There's going to be a great deal of curiosity," he predicts, "about what's happened in the intervening years."

On my flight to Los Angeles the day before meeting Fielding, I pulled out the 407 pages of her new book's closely guarded manuscript, which had been messengered to my apartment the evening before, with a mixture of curiosity and anxiety. (I'd been informed by Fielding's publicist that I should feel flattered to be the first "outside" reader.) I'd gone on record as being a great admirer of the Diary in the face of the anti-Bridget backlash that had followed the book's meteoric appearance (including a Time magazine cover titled "Is Feminism Dead?"), asserting in a New Yorker essay that Bridget's persona was "lit by a spark of genius: she is both Everywoman and an implicitly ironic observer of Every-woman…. One of the pleasures of reading this book is sensing that you're privy to the gossip of the harem—what women talk about when they're not putting a bright face on things." How, I wondered, would Bridget's singleton angst and affection for empowering mantras ("I will not sulk about having no boyfriend, but develop inner poise and authority and sense of self as woman of substance, complete without boyfriend, as best way to obtain boyfriend") hold up all these years later? Would she remain frozen in attitudes that once seemed both clueless and painfully true, obsessing over the circumference of her thighs and whether she'd end up all alone, "half-eaten by an Alsatian," or would she have moved on with the rest of us? Would an older, wiser Bridget even make sense—and if so, what would such a creature sound like?

As it turned out, I needn't have worried. I found myself racing through Mad About the Boy, smiling at the aptness of its observations and frequently laughing aloud. Fielding's comic gifts—and, just as important, her almost anthropological ability to nose out all that is trendy and potentially crazy making about contemporary culture, from Twitter ("OMG, Lady Gaga has 33 million followers! Complete meltdown. Why am I even bothering? Twitter is giant popularity contest which I am doomed to be the worst at") to online dating—are once again on shimmering exhibit. And Bridget, although now a fiftyish single mother who has to deal with putting her two young children, Billy and Mabel, to bed, along with treating their hair for nits, cleaning up vomit, and attending Sports Day school picnics, is still recognizably her ditzy but ultimately unfazable self. Her bevy of friends remain crucial to her well-being, as does her reliance on the self-help canon, which has expanded to include advice on parenting (One, Two, Three…Better, Easier Parenting and French Children Don't Throw Food). She continues to record her caloric intake and to fret about her weight: "Just surveyed self aghast in mirror. Am starting to look like a heron. My legs and arms have stayed the same, but my whole upper body is like a large bird with a big roll of fat round the middle." Most of all, having won and then lost Mark Darcy (I am being intentionally coy here, to avoid setting off a spoiler alert), she continues her search for the right man, in bed and out.

Although Fielding's warmth encourages an easy intimacy, I'm also conscious of the fact that this publicity-shy writer—who tells me that she became "unnerved" by press interest in the wake of Bridget—has agreed to meet with me only on the condition that I focus on her writing and don't push her for details about her personal life. And indeed, embarrassed as I am to admit it, through much of our dinner she interviews me about my response to her book, which she was still putting final touches on in August—quite late by publishing standards. Was that character too much of a cliché? How early on did I guess who Bridget's true romantic interest would be? And the sex parts—were they overwritten?

The ex–book editor in me takes the bait, and Fielding assiduously types my comments into her phone; there's no sign of Bridget-like haphazardness in her approach to her work. Her good friend Carrie Fisher describes her as "an incredibly hard worker. She's a Type A that doesn't seem like a Type A. Her effect is just the opposite: You'd expect her to faint at the sight of blood, but she's in fact going to get the job done."

Later in the evening, when Fielding and I have settled in at the bar for nightcaps, she refers to herself as "a magpie, absorbing other people's ideas from magazines and theories." Although she insists she writes "in a disorganized way," going over what she's written the day before, "highlighting sentences and ditching the rest," Fielding admits to keeping files of information containing "funny things about dating and grooming," among other subjects, with names such as Children's Thoughts ("I think children have an interesting take on things"), Cheerful Bits, and Scheduling. She also keeps no fewer than two diaries, a personal one and a topical diary in which she records her "reaction to stuff in the news or weather."

Fielding, it emerges, never intended to write a third Bridget book. Since 1999, when she became involved with Kevin Curran, a writer and executive producer for The Simpsons, she has been dividing her time between London and L.A.: "I always thought if I were a writer I'd have a swimming pool. I bought a place in L.A. and became a writer with a pool." She stopped writing altogether when she and Curran had children (Romy, seven, and Dash, nine); the couple never married ("I've never wanted to marry," she confides, "that whole bride outfit") and have since broken up, but remain amicable. Fielding tried her hand at a novel set in her native Yorkshire that had, she says, "a horrible portentous tone. I kept coming out with statements…. I dumped it." At that point she started something else—and, lo and behold, "I realized it was her voice again. It just came. It was a story I wanted to tell."

Which brings me, and anyone who's ever warmed to Bridget's endearing mixture of insecurity and bravado, her way of questioning the things we take for granted while feeling bound to go along with the status quo all the same, to ask the inevitable question: Where does Fielding, who refers to her celebrated creation as her "alter ego," leave off and Bridget Jones begin? Are the two more alike than not? Or are they entirely different beings? It's a question that's all the more interesting because Bridget is so specific a character that it's hard to believe that she's been invented from whole cloth—like Madame Bovary, say. And yet on the other hand the novels have the sort of narrative propulsion that is rare in autobiographically conceived fiction, not to mention an unsolipsistic worldview (for all of Bridget's fussing over herself) that invites broad reader identification.

It's clear that the question is one Fielding has given thought to over the years, since Bridget was first hatched. Although she concedes that "a part of me is competent," she also refers to herself as "clumsy and absentminded." Fielding goes on to reflect that while she is always observing herself and others and "sort of laughing," Bridget "doesn't have the distance to look back at the larger picture. I'm not sure," she adds, "that Bridget would actually be able to finish a book—or go on a book tour." Then, too, although both Fielding and her antiheroine are devotees of self-help manuals—"I think it's the new religion," the writer declares. "These books are groping toward rules for living"—the Oxford-educated Fielding doesn't share Bridget's love of TV and herself is a fairly serious reader. (She explains in all earnestness that she's reluctant to turn the TV on, "because I'm frightened it won't work.") Many reviewers have noticed the influence of Jane Austen both in the plotting of the books and in Bridget herself, but Fielding says she's most influenced by the work of nineteenth-century novelists such as Thomas Hardy and Edith Wharton, "where there wasn't the differentiation between a page-turner and a literary novel."

The thing about Fielding I'm most struck by is how down-to-earth she appears to be, despite her enormous success (as of 2009, she was worth an estimated $30 million). She admits to being relieved not to have to worry about money, having once lived "from check to check," but still socializes with the same "mates" she always has. Her biggest pleasure is travel: "That is what I google when I'm supposed to be writing." Indeed, her major worry about becoming a mother was that she might have to cut back on travel, but she ended up taking Dash on 24 flights in his first year.

The other quality that strikes me is how effortless—almost accidental—Fielding makes everything seem, as if her life happened in spite of her. Her trajectory from growing up in Morley, a suburb of Leeds, where she worked in the fabric mills on school holidays and claims that she was "rejected" by one of the many psychopathic assailants who roamed the area because of the unsightly braces and wing-tip glasses she wore as a 14-year-old, to landing a job straight out of university at the BBC (where she insists she was "quite Bridget-like," usually looking "rather startled" on camera, because she could never figure out where to stand) is nothing short of spectacular. Such an ascent must have been powered by a hefty dose of youthful ambition. To hear Fielding tell it, she lucked out a lot and then often mucked things up, only to get back on her feet again. She admits that going to Oxford, where she met Rowan Atkinson and Richard Curtis (the latter would be her cowriter on the first Bridget Jones script), was "not typical" for someone from her working-class background: "I got in there," she says, "and felt I had peaked." But she then recalls that she felt "out of place" and "defensive" about where she was from, adding: "I could have gotten more out of it academically." Similarly, she says that when she started writing restaurant reviews, she'd look down at her notes and glimpse just one word: Pudding.

Fisher pinpoints Fielding's unusual way of relating to people, the very same style that has led me to feel after our dinner that I know her well and yet not at all, by noting that "she's cautious in a way that makes you feel she's intimate with you." The actress theorizes that Fielding has "an unusual combination of characteristics you don't usually find in one person. She's a great audience and a great performer. She questions herself and doesn't take things for granted. She's all this shit; it's annoying," Fisher concludes. "I want to be like her, and I don't hate her for wanting to be like her."

When I ask Curtis what she was like way back when, at Oxford, he e-mails me from Rio de Janeiro: "What I can say is that she was definitely always funny—that was the sign she'd write Bridget…. While many other people were trying to show they were serious and took themselves seriously, Helen always laughed at herself." To my point that I can't discern any objectionable traits in Fielding, he says: "Gosh. Of course there are things wrong with Helly…. She can be very stupid. She wanted Bridget 2 to be exactly the same length as Bridget 1, so she counted the number of pages in 1 and wrote exactly the same number of pages for 2. But forgot she had double-spaced the first book, so ended up with a book exactly twice the length—but then couldn't be bothered to cut it down."

So, it may be going down the wrong track to try and parse out where Bridget Jones stops and Helen Fielding begins, if only because the two seem both complexly intertwined and complexly different from each other. What they undoubtedly share is an acute perception of the discrepancy between our public and private selves—the gap, as Fielding puts it, "between who you are and the expectation"—just as both of them are truth tellers, in their way, refusing to yield to the politically correct dictates of our age. When, for instance, we go near the subject of whether Bridget is too concerned, as some critics have argued, with her appearance, Fielding turns outright fierce on behalf of her fictional counterpart: "For anyone to question our obsession with looks in this day and age is an absurdity," she declares. "You cannot walk down any street without pictures of airbrushed women and idealized images of beauty being shoved at you all the time."

It is almost midnight when Fielding and I finish up our conversation at the Chateau Marmont. I feel reluctant to let her go, in part because I feel like I haven't done enough Lois Lane–like reporting, and in part because I feel like I've found a kindred spirit—only one who may be several steps ahead of me in figuring it all out while staying true to her moral compass. "I think far too much," Fielding confides, "especially when I write a book. I'm really lost in it—I've taken off into another world." Although she professes a desire to think less—"I'd like to be more vacant," she announces—there doesn't seem much chance of that happening anytime soon. These days Fielding is working on the musical of Bridget Jones's Diary, for which she's written the script and now is collaborating on songs with Lily Allen, and there's undoubt-edly a screen version of Bridget Jones: Mad About the Boy to come. Meanwhile, she has two young children to keep her busy as she tries to ward off the intrusions of a looksist society by "keeping mirrors to a minimum in my house" and works on "being kind, honest, friendly, vulnerable, warm—those things that aren't currency in the media world." How else to put it? The woman who invented one of the most iconic fictional protagonists in recent memory and along the way invented a new genre that has yet to live up to her standard is one lovely, easy-to-identify-with mess.